[deliverable/linux.git] / drivers / iio / industrialio-event.c

/* Industrial I/O event handling
 *
 * Copyright (c) 2008 Jonathan Cameron
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 * Based on elements of hwmon and input subsystems.
 */

#include <linux/anon_inodes.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/kfifo.h>
#include <linux/module.h>
#include <linux/poll.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/wait.h>
#include <linux/iio/iio.h>
#include "iio_core.h"
#include <linux/iio/sysfs.h>
#include <linux/iio/events.h>

/**
 * struct iio_event_interface - chrdev interface for an event line
 * @wait:		wait queue to allow blocking reads of events
 * @det_events:		list of detected events
 * @dev_attr_list:	list of event interface sysfs attribute
 * @flags:		file operations related flags including busy flag.
 * @group:		event interface sysfs attribute group
 */
struct iio_event_interface {
	wait_queue_head_t	wait;
	DECLARE_KFIFO(det_events, struct iio_event_data, 16);

	struct list_head	dev_attr_list;
	unsigned long		flags;
	struct attribute_group	group;
};

int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp)
{
	struct iio_event_interface *ev_int = indio_dev->event_interface;
	struct iio_event_data ev;
	unsigned long flags;
	int copied;

	/* Does anyone care? */
	spin_lock_irqsave(&ev_int->wait.lock, flags);
	if (test_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) {

		ev.id = ev_code;
		ev.timestamp = timestamp;

		copied = kfifo_put(&ev_int->det_events, &ev);
		if (copied != 0)
			wake_up_locked_poll(&ev_int->wait, POLLIN);
	}
	spin_unlock_irqrestore(&ev_int->wait.lock, flags);

	return 0;
}
EXPORT_SYMBOL(iio_push_event);

/**
 * iio_event_poll() - poll the event queue to find out if it has data
 */
static unsigned int iio_event_poll(struct file *filep,
			     struct poll_table_struct *wait)
{
	struct iio_dev *indio_dev = filep->private_data;
	struct iio_event_interface *ev_int = indio_dev->event_interface;
	unsigned int events = 0;

	if (!indio_dev->info)
		return -ENODEV;

	poll_wait(filep, &ev_int->wait, wait);

	spin_lock_irq(&ev_int->wait.lock);
	if (!kfifo_is_empty(&ev_int->det_events))
		events = POLLIN | POLLRDNORM;
	spin_unlock_irq(&ev_int->wait.lock);

	return events;
}

static ssize_t iio_event_chrdev_read(struct file *filep,
				     char __user *buf,
				     size_t count,
				     loff_t *f_ps)
{
	struct iio_dev *indio_dev = filep->private_data;
	struct iio_event_interface *ev_int = indio_dev->event_interface;
	unsigned int copied;
	int ret;

	if (!indio_dev->info)
		return -ENODEV;

	if (count < sizeof(struct iio_event_data))
		return -EINVAL;

	spin_lock_irq(&ev_int->wait.lock);
	if (kfifo_is_empty(&ev_int->det_events)) {
		if (filep->f_flags & O_NONBLOCK) {
			ret = -EAGAIN;
			goto error_unlock;
		}
		/* Blocking on device; waiting for something to be there */
		ret = wait_event_interruptible_locked_irq(ev_int->wait,
					!kfifo_is_empty(&ev_int->det_events) ||
					indio_dev->info == NULL);
		if (ret)
			goto error_unlock;
		if (indio_dev->info == NULL) {
			ret = -ENODEV;
			goto error_unlock;
		}
		/* Single access device so no one else can get the data */
	}

	ret = kfifo_to_user(&ev_int->det_events, buf, count, &copied);

error_unlock:
	spin_unlock_irq(&ev_int->wait.lock);

	return ret ? ret : copied;
}

static int iio_event_chrdev_release(struct inode *inode, struct file *filep)
{
	struct iio_dev *indio_dev = filep->private_data;
	struct iio_event_interface *ev_int = indio_dev->event_interface;

	spin_lock_irq(&ev_int->wait.lock);
	__clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
	/*
	 * In order to maintain a clean state for reopening,
	 * clear out any awaiting events. The mask will prevent
	 * any new __iio_push_event calls running.
	 */
	kfifo_reset_out(&ev_int->det_events);
	spin_unlock_irq(&ev_int->wait.lock);

	iio_device_put(indio_dev);

	return 0;
}

static const struct file_operations iio_event_chrdev_fileops = {
	.read =  iio_event_chrdev_read,
	.poll =  iio_event_poll,
	.release = iio_event_chrdev_release,
	.owner = THIS_MODULE,
	.llseek = noop_llseek,
};

int iio_event_getfd(struct iio_dev *indio_dev)
{
	struct iio_event_interface *ev_int = indio_dev->event_interface;
	int fd;

	if (ev_int == NULL)
		return -ENODEV;

	spin_lock_irq(&ev_int->wait.lock);
	if (__test_and_set_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) {
		spin_unlock_irq(&ev_int->wait.lock);
		return -EBUSY;
	}
	spin_unlock_irq(&ev_int->wait.lock);
	iio_device_get(indio_dev);

	fd = anon_inode_getfd("iio:event", &iio_event_chrdev_fileops,
				indio_dev, O_RDONLY | O_CLOEXEC);
	if (fd < 0) {
		spin_lock_irq(&ev_int->wait.lock);
		__clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
		spin_unlock_irq(&ev_int->wait.lock);
		iio_device_put(indio_dev);
	}
	return fd;
}

static const char * const iio_ev_type_text[] = {
	[IIO_EV_TYPE_THRESH] = "thresh",
	[IIO_EV_TYPE_MAG] = "mag",
	[IIO_EV_TYPE_ROC] = "roc",
	[IIO_EV_TYPE_THRESH_ADAPTIVE] = "thresh_adaptive",
	[IIO_EV_TYPE_MAG_ADAPTIVE] = "mag_adaptive",
};

static const char * const iio_ev_dir_text[] = {
	[IIO_EV_DIR_EITHER] = "either",
	[IIO_EV_DIR_RISING] = "rising",
	[IIO_EV_DIR_FALLING] = "falling"
};

static ssize_t iio_ev_state_store(struct device *dev,
				  struct device_attribute *attr,
				  const char *buf,
				  size_t len)
{
	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
	int ret;
	bool val;

	ret = strtobool(buf, &val);
	if (ret < 0)
		return ret;

	ret = indio_dev->info->write_event_config(indio_dev,
						  this_attr->address,
						  val);
	return (ret < 0) ? ret : len;
}

static ssize_t iio_ev_state_show(struct device *dev,
				 struct device_attribute *attr,
				 char *buf)
{
	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
	int val = indio_dev->info->read_event_config(indio_dev,
						     this_attr->address);

	if (val < 0)
		return val;
	else
		return sprintf(buf, "%d\n", val);
}

static ssize_t iio_ev_value_show(struct device *dev,
				 struct device_attribute *attr,
				 char *buf)
{
	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
	int val, ret;

	ret = indio_dev->info->read_event_value(indio_dev,
						this_attr->address, &val);
	if (ret < 0)
		return ret;

	return sprintf(buf, "%d\n", val);
}

static ssize_t iio_ev_value_store(struct device *dev,
				  struct device_attribute *attr,
				  const char *buf,
				  size_t len)
{
	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
	int val;
	int ret;

	if (!indio_dev->info->write_event_value)
		return -EINVAL;

	ret = kstrtoint(buf, 10, &val);
	if (ret)
		return ret;

	ret = indio_dev->info->write_event_value(indio_dev, this_attr->address,
						 val);
	if (ret < 0)
		return ret;

	return len;
}

static int iio_device_add_event_sysfs(struct iio_dev *indio_dev,
				      struct iio_chan_spec const *chan)
{
	int ret = 0, i, attrcount = 0;
	u64 mask = 0;
	char *postfix;
	if (!chan->event_mask)
		return 0;

	for_each_set_bit(i, &chan->event_mask, sizeof(chan->event_mask)*8) {
		postfix = kasprintf(GFP_KERNEL, "%s_%s_en",
				    iio_ev_type_text[i/IIO_EV_DIR_MAX],
				    iio_ev_dir_text[i%IIO_EV_DIR_MAX]);
		if (postfix == NULL) {
			ret = -ENOMEM;
			goto error_ret;
		}
		if (chan->modified)
			mask = IIO_MOD_EVENT_CODE(chan->type, 0, chan->channel2,
						  i/IIO_EV_DIR_MAX,
						  i%IIO_EV_DIR_MAX);
		else if (chan->differential)
			mask = IIO_EVENT_CODE(chan->type,
					      0, 0,
					      i%IIO_EV_DIR_MAX,
					      i/IIO_EV_DIR_MAX,
					      0,
					      chan->channel,
					      chan->channel2);
		else
			mask = IIO_UNMOD_EVENT_CODE(chan->type,
						    chan->channel,
						    i/IIO_EV_DIR_MAX,
						    i%IIO_EV_DIR_MAX);

		ret = __iio_add_chan_devattr(postfix,
					     chan,
					     &iio_ev_state_show,
					     iio_ev_state_store,
					     mask,
					     0,
					     &indio_dev->dev,
					     &indio_dev->event_interface->
					     dev_attr_list);
		kfree(postfix);
		if (ret)
			goto error_ret;
		attrcount++;
		postfix = kasprintf(GFP_KERNEL, "%s_%s_value",
				    iio_ev_type_text[i/IIO_EV_DIR_MAX],
				    iio_ev_dir_text[i%IIO_EV_DIR_MAX]);
		if (postfix == NULL) {
			ret = -ENOMEM;
			goto error_ret;
		}
		ret = __iio_add_chan_devattr(postfix, chan,
					     iio_ev_value_show,
					     iio_ev_value_store,
					     mask,
					     0,
					     &indio_dev->dev,
					     &indio_dev->event_interface->
					     dev_attr_list);
		kfree(postfix);
		if (ret)
			goto error_ret;
		attrcount++;
	}
	ret = attrcount;
error_ret:
	return ret;
}

static inline void __iio_remove_event_config_attrs(struct iio_dev *indio_dev)
{
	struct iio_dev_attr *p, *n;
	list_for_each_entry_safe(p, n,
				 &indio_dev->event_interface->
				 dev_attr_list, l) {
		kfree(p->dev_attr.attr.name);
		kfree(p);
	}
}

static inline int __iio_add_event_config_attrs(struct iio_dev *indio_dev)
{
	int j, ret, attrcount = 0;

	/* Dynically created from the channels array */
	for (j = 0; j < indio_dev->num_channels; j++) {
		ret = iio_device_add_event_sysfs(indio_dev,
						 &indio_dev->channels[j]);
		if (ret < 0)
			return ret;
		attrcount += ret;
	}
	return attrcount;
}

static bool iio_check_for_dynamic_events(struct iio_dev *indio_dev)
{
	int j;

	for (j = 0; j < indio_dev->num_channels; j++)
		if (indio_dev->channels[j].event_mask != 0)
			return true;
	return false;
}

static void iio_setup_ev_int(struct iio_event_interface *ev_int)
{
	INIT_KFIFO(ev_int->det_events);
	init_waitqueue_head(&ev_int->wait);
}

static const char *iio_event_group_name = "events";
int iio_device_register_eventset(struct iio_dev *indio_dev)
{
	struct iio_dev_attr *p;
	int ret = 0, attrcount_orig = 0, attrcount, attrn;
	struct attribute **attr;

	if (!(indio_dev->info->event_attrs ||
	      iio_check_for_dynamic_events(indio_dev)))
		return 0;

	indio_dev->event_interface =
		kzalloc(sizeof(struct iio_event_interface), GFP_KERNEL);
	if (indio_dev->event_interface == NULL) {
		ret = -ENOMEM;
		goto error_ret;
	}

	INIT_LIST_HEAD(&indio_dev->event_interface->dev_attr_list);

	iio_setup_ev_int(indio_dev->event_interface);
	if (indio_dev->info->event_attrs != NULL) {
		attr = indio_dev->info->event_attrs->attrs;
		while (*attr++ != NULL)
			attrcount_orig++;
	}
	attrcount = attrcount_orig;
	if (indio_dev->channels) {
		ret = __iio_add_event_config_attrs(indio_dev);
		if (ret < 0)
			goto error_free_setup_event_lines;
		attrcount += ret;
	}

	indio_dev->event_interface->group.name = iio_event_group_name;
	indio_dev->event_interface->group.attrs = kcalloc(attrcount + 1,
							  sizeof(indio_dev->event_interface->group.attrs[0]),
							  GFP_KERNEL);
	if (indio_dev->event_interface->group.attrs == NULL) {
		ret = -ENOMEM;
		goto error_free_setup_event_lines;
	}
	if (indio_dev->info->event_attrs)
		memcpy(indio_dev->event_interface->group.attrs,
		       indio_dev->info->event_attrs->attrs,
		       sizeof(indio_dev->event_interface->group.attrs[0])
		       *attrcount_orig);
	attrn = attrcount_orig;
	/* Add all elements from the list. */
	list_for_each_entry(p,
			    &indio_dev->event_interface->dev_attr_list,
			    l)
		indio_dev->event_interface->group.attrs[attrn++] =
			&p->dev_attr.attr;
	indio_dev->groups[indio_dev->groupcounter++] =
		&indio_dev->event_interface->group;

	return 0;

error_free_setup_event_lines:
	__iio_remove_event_config_attrs(indio_dev);
	kfree(indio_dev->event_interface);
error_ret:

	return ret;
}

/**
 * iio_device_wakeup_eventset - Wakes up the event waitqueue
 * @indio_dev: The IIO device
 *
 * Wakes up the event waitqueue used for poll() and blocking read().
 * Should usually be called when the device is unregistered.
 */
void iio_device_wakeup_eventset(struct iio_dev *indio_dev)
{
	if (indio_dev->event_interface == NULL)
		return;
	wake_up(&indio_dev->event_interface->wait);
}

void iio_device_unregister_eventset(struct iio_dev *indio_dev)
{
	if (indio_dev->event_interface == NULL)
		return;
	__iio_remove_event_config_attrs(indio_dev);
	kfree(indio_dev->event_interface->group.attrs);
	kfree(indio_dev->event_interface);
}
Commit	Line	Data
0a769a95 LPC	1	/* Industrial I/O event handling
	2	*
	3	* Copyright (c) 2008 Jonathan Cameron
	4	*
	5	* This program is free software; you can redistribute it and/or modify it
	6	* under the terms of the GNU General Public License version 2 as published by
	7	* the Free Software Foundation.
	8	*
	9	* Based on elements of hwmon and input subsystems.
	10	*/
	11
	12	#include <linux/anon_inodes.h>
	13	#include <linux/device.h>
	14	#include <linux/fs.h>
	15	#include <linux/kernel.h>
2c00193f	16	#include <linux/kfifo.h>
0a769a95	17	#include <linux/module.h>
e18045ed	18	#include <linux/poll.h>
0a769a95 LPC	19	#include <linux/sched.h>
	20	#include <linux/slab.h>
	21	#include <linux/uaccess.h>
	22	#include <linux/wait.h>
06458e27	23	#include <linux/iio/iio.h>
0a769a95	24	#include "iio_core.h"
06458e27 JC	25	#include <linux/iio/sysfs.h>
06458e27 JC	26	#include <linux/iio/events.h>
0a769a95	27
0a769a95 LPC	28	/**
	29	* struct iio_event_interface - chrdev interface for an event line
	30	* @wait: wait queue to allow blocking reads of events
0a769a95	31	* @det_events: list of detected events
0a769a95 LPC	32	* @dev_attr_list: list of event interface sysfs attribute
	33	* @flags: file operations related flags including busy flag.
	34	* @group: event interface sysfs attribute group
	35	*/
	36	struct iio_event_interface {
	37	wait_queue_head_t wait;
2c00193f LPC	38	DECLARE_KFIFO(det_events, struct iio_event_data, 16);
2c00193f LPC	39
0a769a95 LPC	40	struct list_head dev_attr_list;
	41	unsigned long flags;
	42	struct attribute_group group;
	43	};
	44
	45	int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp)
	46	{
	47	struct iio_event_interface *ev_int = indio_dev->event_interface;
2c00193f	48	struct iio_event_data ev;
1b9dc91e	49	unsigned long flags;
2c00193f	50	int copied;
0a769a95 LPC	51
0a769a95 LPC	52	/* Does anyone care? */
1b9dc91e	53	spin_lock_irqsave(&ev_int->wait.lock, flags);
0a769a95	54	if (test_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) {
0a769a95	55
2c00193f LPC	56	ev.id = ev_code;
	57	ev.timestamp = timestamp;
	58
	59	copied = kfifo_put(&ev_int->det_events, &ev);
2c00193f	60	if (copied != 0)
e18045ed	61	wake_up_locked_poll(&ev_int->wait, POLLIN);
43ba1100	62	}
1b9dc91e	63	spin_unlock_irqrestore(&ev_int->wait.lock, flags);
0a769a95	64
2c00193f	65	return 0;
0a769a95 LPC	66	}
	67	EXPORT_SYMBOL(iio_push_event);
	68
e18045ed LPC	69	/**
	70	* iio_event_poll() - poll the event queue to find out if it has data
	71	*/
	72	static unsigned int iio_event_poll(struct file *filep,
	73	struct poll_table_struct *wait)
	74	{
cadc2125 LPC	75	struct iio_dev *indio_dev = filep->private_data;
cadc2125 LPC	76	struct iio_event_interface *ev_int = indio_dev->event_interface;
e18045ed LPC	77	unsigned int events = 0;
e18045ed LPC	78
f18e7a06 LPC	79	if (!indio_dev->info)
	80	return -ENODEV;
	81
e18045ed LPC	82	poll_wait(filep, &ev_int->wait, wait);
e18045ed LPC	83
1b9dc91e	84	spin_lock_irq(&ev_int->wait.lock);
e18045ed LPC	85	if (!kfifo_is_empty(&ev_int->det_events))
e18045ed LPC	86	events = POLLIN \| POLLRDNORM;
1b9dc91e	87	spin_unlock_irq(&ev_int->wait.lock);
e18045ed LPC	88
	89	return events;
	90	}
	91
0a769a95 LPC	92	static ssize_t iio_event_chrdev_read(struct file *filep,
	93	char __user *buf,
	94	size_t count,
	95	loff_t *f_ps)
	96	{
cadc2125 LPC	97	struct iio_dev *indio_dev = filep->private_data;
cadc2125 LPC	98	struct iio_event_interface *ev_int = indio_dev->event_interface;
2c00193f	99	unsigned int copied;
0a769a95 LPC	100	int ret;
0a769a95 LPC	101
f18e7a06 LPC	102	if (!indio_dev->info)
	103	return -ENODEV;
	104
2c00193f	105	if (count < sizeof(struct iio_event_data))
0a769a95 LPC	106	return -EINVAL;
0a769a95 LPC	107
1b9dc91e	108	spin_lock_irq(&ev_int->wait.lock);
2c00193f	109	if (kfifo_is_empty(&ev_int->det_events)) {
0a769a95 LPC	110	if (filep->f_flags & O_NONBLOCK) {
0a769a95 LPC	111	ret = -EAGAIN;
43ba1100	112	goto error_unlock;
0a769a95	113	}
0a769a95	114	/* Blocking on device; waiting for something to be there */
1b9dc91e	115	ret = wait_event_interruptible_locked_irq(ev_int->wait,
d2f0a48f LPC	116	!kfifo_is_empty(&ev_int->det_events) \|\|
d2f0a48f LPC	117	indio_dev->info == NULL);
0a769a95	118	if (ret)
43ba1100	119	goto error_unlock;
d2f0a48f LPC	120	if (indio_dev->info == NULL) {
	121	ret = -ENODEV;
	122	goto error_unlock;
	123	}
0a769a95	124	/* Single access device so no one else can get the data */
0a769a95 LPC	125	}
0a769a95 LPC	126
2c00193f	127	ret = kfifo_to_user(&ev_int->det_events, buf, count, &copied);
0a769a95	128
43ba1100	129	error_unlock:
1b9dc91e	130	spin_unlock_irq(&ev_int->wait.lock);
43ba1100	131
2c00193f	132	return ret ? ret : copied;
0a769a95 LPC	133	}
	134
	135	static int iio_event_chrdev_release(struct inode inode, struct file filep)
	136	{
cadc2125 LPC	137	struct iio_dev *indio_dev = filep->private_data;
cadc2125 LPC	138	struct iio_event_interface *ev_int = indio_dev->event_interface;
0a769a95	139
1b9dc91e	140	spin_lock_irq(&ev_int->wait.lock);
a046c1e8	141	__clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
0a769a95 LPC	142	/*
	143	* In order to maintain a clean state for reopening,
	144	* clear out any awaiting events. The mask will prevent
	145	* any new __iio_push_event calls running.
	146	*/
2c00193f	147	kfifo_reset_out(&ev_int->det_events);
1b9dc91e	148	spin_unlock_irq(&ev_int->wait.lock);
0a769a95	149
cadc2125 LPC	150	iio_device_put(indio_dev);
cadc2125 LPC	151
0a769a95 LPC	152	return 0;
	153	}
	154
	155	static const struct file_operations iio_event_chrdev_fileops = {
	156	.read = iio_event_chrdev_read,
e18045ed	157	.poll = iio_event_poll,
0a769a95 LPC	158	.release = iio_event_chrdev_release,
	159	.owner = THIS_MODULE,
	160	.llseek = noop_llseek,
	161	};
	162
	163	int iio_event_getfd(struct iio_dev *indio_dev)
	164	{
	165	struct iio_event_interface *ev_int = indio_dev->event_interface;
	166	int fd;
	167
	168	if (ev_int == NULL)
	169	return -ENODEV;
	170
1b9dc91e	171	spin_lock_irq(&ev_int->wait.lock);
a046c1e8	172	if (__test_and_set_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) {
1b9dc91e	173	spin_unlock_irq(&ev_int->wait.lock);
0a769a95 LPC	174	return -EBUSY;
0a769a95 LPC	175	}
1b9dc91e	176	spin_unlock_irq(&ev_int->wait.lock);
cadc2125 LPC	177	iio_device_get(indio_dev);
	178
	179	fd = anon_inode_getfd("iio:event", &iio_event_chrdev_fileops,
e2aad1d5	180	indio_dev, O_RDONLY \| O_CLOEXEC);
0a769a95	181	if (fd < 0) {
1b9dc91e	182	spin_lock_irq(&ev_int->wait.lock);
a046c1e8	183	__clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
1b9dc91e	184	spin_unlock_irq(&ev_int->wait.lock);
cadc2125	185	iio_device_put(indio_dev);
0a769a95 LPC	186	}
	187	return fd;
	188	}
	189
	190	static const char * const iio_ev_type_text[] = {
	191	[IIO_EV_TYPE_THRESH] = "thresh",
	192	[IIO_EV_TYPE_MAG] = "mag",
	193	[IIO_EV_TYPE_ROC] = "roc",
	194	[IIO_EV_TYPE_THRESH_ADAPTIVE] = "thresh_adaptive",
	195	[IIO_EV_TYPE_MAG_ADAPTIVE] = "mag_adaptive",
	196	};
	197
	198	static const char * const iio_ev_dir_text[] = {
	199	[IIO_EV_DIR_EITHER] = "either",
	200	[IIO_EV_DIR_RISING] = "rising",
	201	[IIO_EV_DIR_FALLING] = "falling"
	202	};
	203
	204	static ssize_t iio_ev_state_store(struct device *dev,
	205	struct device_attribute *attr,
	206	const char *buf,
	207	size_t len)
	208	{
e53f5ac5	209	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
0a769a95 LPC	210	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
	211	int ret;
	212	bool val;
	213
	214	ret = strtobool(buf, &val);
	215	if (ret < 0)
	216	return ret;
	217
	218	ret = indio_dev->info->write_event_config(indio_dev,
	219	this_attr->address,
	220	val);
	221	return (ret < 0) ? ret : len;
	222	}
	223
	224	static ssize_t iio_ev_state_show(struct device *dev,
	225	struct device_attribute *attr,
	226	char *buf)
	227	{
e53f5ac5	228	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
0a769a95 LPC	229	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
	230	int val = indio_dev->info->read_event_config(indio_dev,
	231	this_attr->address);
	232
	233	if (val < 0)
	234	return val;
	235	else
	236	return sprintf(buf, "%d\n", val);
	237	}
	238
	239	static ssize_t iio_ev_value_show(struct device *dev,
	240	struct device_attribute *attr,
	241	char *buf)
	242	{
e53f5ac5	243	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
0a769a95 LPC	244	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
	245	int val, ret;
	246
	247	ret = indio_dev->info->read_event_value(indio_dev,
	248	this_attr->address, &val);
	249	if (ret < 0)
	250	return ret;
	251
	252	return sprintf(buf, "%d\n", val);
	253	}
	254
	255	static ssize_t iio_ev_value_store(struct device *dev,
	256	struct device_attribute *attr,
	257	const char *buf,
	258	size_t len)
	259	{
e53f5ac5	260	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
0a769a95	261	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
948ad205	262	int val;
0a769a95 LPC	263	int ret;
	264
	265	if (!indio_dev->info->write_event_value)
	266	return -EINVAL;
	267
948ad205	268	ret = kstrtoint(buf, 10, &val);
0a769a95 LPC	269	if (ret)
	270	return ret;
	271
	272	ret = indio_dev->info->write_event_value(indio_dev, this_attr->address,
	273	val);
	274	if (ret < 0)
	275	return ret;
	276
	277	return len;
	278	}
	279
	280	static int iio_device_add_event_sysfs(struct iio_dev *indio_dev,
	281	struct iio_chan_spec const *chan)
	282	{
	283	int ret = 0, i, attrcount = 0;
	284	u64 mask = 0;
	285	char *postfix;
	286	if (!chan->event_mask)
	287	return 0;
	288
	289	for_each_set_bit(i, &chan->event_mask, sizeof(chan->event_mask)*8) {
	290	postfix = kasprintf(GFP_KERNEL, "%s_%s_en",
	291	iio_ev_type_text[i/IIO_EV_DIR_MAX],
	292	iio_ev_dir_text[i%IIO_EV_DIR_MAX]);
	293	if (postfix == NULL) {
	294	ret = -ENOMEM;
	295	goto error_ret;
	296	}
	297	if (chan->modified)
2b0774df	298	mask = IIO_MOD_EVENT_CODE(chan->type, 0, chan->channel2,
0a769a95 LPC	299	i/IIO_EV_DIR_MAX,
	300	i%IIO_EV_DIR_MAX);
	301	else if (chan->differential)
	302	mask = IIO_EVENT_CODE(chan->type,
	303	0, 0,
	304	i%IIO_EV_DIR_MAX,
	305	i/IIO_EV_DIR_MAX,
	306	0,
	307	chan->channel,
	308	chan->channel2);
	309	else
	310	mask = IIO_UNMOD_EVENT_CODE(chan->type,
	311	chan->channel,
	312	i/IIO_EV_DIR_MAX,
	313	i%IIO_EV_DIR_MAX);
	314
	315	ret = __iio_add_chan_devattr(postfix,
	316	chan,
	317	&iio_ev_state_show,
	318	iio_ev_state_store,
	319	mask,
	320	0,
	321	&indio_dev->dev,
	322	&indio_dev->event_interface->
	323	dev_attr_list);
	324	kfree(postfix);
	325	if (ret)
	326	goto error_ret;
	327	attrcount++;
	328	postfix = kasprintf(GFP_KERNEL, "%s_%s_value",
	329	iio_ev_type_text[i/IIO_EV_DIR_MAX],
	330	iio_ev_dir_text[i%IIO_EV_DIR_MAX]);
	331	if (postfix == NULL) {
	332	ret = -ENOMEM;
	333	goto error_ret;
	334	}
	335	ret = __iio_add_chan_devattr(postfix, chan,
	336	iio_ev_value_show,
	337	iio_ev_value_store,
	338	mask,
	339	0,
	340	&indio_dev->dev,
	341	&indio_dev->event_interface->
	342	dev_attr_list);
	343	kfree(postfix);
	344	if (ret)
	345	goto error_ret;
	346	attrcount++;
	347	}
	348	ret = attrcount;
	349	error_ret:
	350	return ret;
	351	}
	352
	353	static inline void __iio_remove_event_config_attrs(struct iio_dev *indio_dev)
	354	{
	355	struct iio_dev_attr p, n;
	356	list_for_each_entry_safe(p, n,
	357	&indio_dev->event_interface->
	358	dev_attr_list, l) {
	359	kfree(p->dev_attr.attr.name);
	360	kfree(p);
	361	}
	362	}
363
364	static inline int __iio_add_event_config_attrs(struct iio_dev *indio_dev)
365	{
366	int j, ret, attrcount = 0;
367
0a769a95 LPC	368	/* Dynically created from the channels array */
	369	for (j = 0; j < indio_dev->num_channels; j++) {
	370	ret = iio_device_add_event_sysfs(indio_dev,
	371	&indio_dev->channels[j]);
	372	if (ret < 0)
e3db9ef6	373	return ret;
0a769a95 LPC	374	attrcount += ret;
	375	}
	376	return attrcount;
0a769a95 LPC	377	}
	378
	379	static bool iio_check_for_dynamic_events(struct iio_dev *indio_dev)
	380	{
	381	int j;
	382
	383	for (j = 0; j < indio_dev->num_channels; j++)
	384	if (indio_dev->channels[j].event_mask != 0)
	385	return true;
	386	return false;
	387	}
	388
	389	static void iio_setup_ev_int(struct iio_event_interface *ev_int)
	390	{
2c00193f	391	INIT_KFIFO(ev_int->det_events);
0a769a95 LPC	392	init_waitqueue_head(&ev_int->wait);
	393	}
	394
	395	static const char *iio_event_group_name = "events";
	396	int iio_device_register_eventset(struct iio_dev *indio_dev)
	397	{
	398	struct iio_dev_attr *p;
	399	int ret = 0, attrcount_orig = 0, attrcount, attrn;
	400	struct attribute **attr;
	401
	402	if (!(indio_dev->info->event_attrs \|\|
	403	iio_check_for_dynamic_events(indio_dev)))
	404	return 0;
	405
	406	indio_dev->event_interface =
	407	kzalloc(sizeof(struct iio_event_interface), GFP_KERNEL);
	408	if (indio_dev->event_interface == NULL) {
	409	ret = -ENOMEM;
	410	goto error_ret;
	411	}
	412
46b24311 SH	413	INIT_LIST_HEAD(&indio_dev->event_interface->dev_attr_list);
46b24311 SH	414
0a769a95 LPC	415	iio_setup_ev_int(indio_dev->event_interface);
	416	if (indio_dev->info->event_attrs != NULL) {
	417	attr = indio_dev->info->event_attrs->attrs;
	418	while (*attr++ != NULL)
	419	attrcount_orig++;
	420	}
	421	attrcount = attrcount_orig;
	422	if (indio_dev->channels) {
	423	ret = __iio_add_event_config_attrs(indio_dev);
	424	if (ret < 0)
	425	goto error_free_setup_event_lines;
	426	attrcount += ret;
	427	}
	428
	429	indio_dev->event_interface->group.name = iio_event_group_name;
	430	indio_dev->event_interface->group.attrs = kcalloc(attrcount + 1,
	431	sizeof(indio_dev->event_interface->group.attrs[0]),
	432	GFP_KERNEL);
	433	if (indio_dev->event_interface->group.attrs == NULL) {
	434	ret = -ENOMEM;
	435	goto error_free_setup_event_lines;
	436	}
	437	if (indio_dev->info->event_attrs)
	438	memcpy(indio_dev->event_interface->group.attrs,
	439	indio_dev->info->event_attrs->attrs,
	440	sizeof(indio_dev->event_interface->group.attrs[0])
	441	*attrcount_orig);
	442	attrn = attrcount_orig;
	443	/* Add all elements from the list. */
	444	list_for_each_entry(p,
	445	&indio_dev->event_interface->dev_attr_list,
	446	l)
	447	indio_dev->event_interface->group.attrs[attrn++] =
	448	&p->dev_attr.attr;
	449	indio_dev->groups[indio_dev->groupcounter++] =
	450	&indio_dev->event_interface->group;
	451
	452	return 0;
	453
	454	error_free_setup_event_lines:
	455	__iio_remove_event_config_attrs(indio_dev);
	456	kfree(indio_dev->event_interface);
	457	error_ret:
	458
	459	return ret;
	460	}
	461
d2f0a48f LPC	462	/**
	463	* iio_device_wakeup_eventset - Wakes up the event waitqueue
	464	* @indio_dev: The IIO device
	465	*
	466	* Wakes up the event waitqueue used for poll() and blocking read().
	467	* Should usually be called when the device is unregistered.
	468	*/
	469	void iio_device_wakeup_eventset(struct iio_dev *indio_dev)
	470	{
	471	if (indio_dev->event_interface == NULL)
	472	return;
	473	wake_up(&indio_dev->event_interface->wait);
	474	}
	475
0a769a95 LPC	476	void iio_device_unregister_eventset(struct iio_dev *indio_dev)
	477	{
	478	if (indio_dev->event_interface == NULL)
	479	return;
	480	__iio_remove_event_config_attrs(indio_dev);
	481	kfree(indio_dev->event_interface->group.attrs);
	482	kfree(indio_dev->event_interface);
	483	}